Godet roll for guiding, heating and conveying yarn

ABSTRACT

A godet roll for guiding, heating and conveying yarn on the circumference of a hollow-cylindrical godet roll casing. The godet roll casing is seated on a projecting support by at least one magnetic bearing having bearing pole windings, and a heating device with heating pole windings is arranged on the support. Some bearing pole windings and at least one heating pole winding are arranged together in one bearing plane, so that the bearing areas can be heated. Sensors provided for detecting the position of the godet roll casing are arranged outside of an annular chamber formed between the godet roll casing and the support in order to prevent a thermal overload of the sensors.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of German patent application 101 04424.0 filed Feb. 1, 2001, herein incorporated by reference and is acontinuation of U.S. patent application Ser. No. 10/061,610, filed Feb.1, 2002 now U.S. Pat. No. 6,717,309.

FIELD OF THE INVENTION

The present invention relates generally to a godet roll for guiding,heating and conveying yarn. More particularly, the present inventionrelates to such a godet roll comprising a projecting support, a drivablehollow-cylindrical godet roll casing forming a circumferential yarnguiding surface, at least one radially acting bearing rotatably seatingthe godet roll casing on the projecting support in at least one bearingplane, the radially acting bearing comprising a plurality of bearingpole windings, and a heating device comprising a plurality of heatingpole windings on the support, the bearing pole windings and the heatingpole windings being arranged within an annular chamber between thesupport and the godet roll casing.

BACKGROUND OF THE INVENTION

A godet roll of the above-described type to which the invention relatesis disclosed in European Patent Publication EP 0 770 719 B1. This knowngodet roll heats a rotatably seated godet roll casing, on thecircumference of which one or more yarns are guided. The godet rollcasing is embodied to be cylindrical and hollow and is seated by meansof several magnetic bearings on a projecting support. In addition to themagnetic bearings, a heating device for heating the godet roll casing isarranged in an annular chamber formed between the support and the godetroll casing. Basically, two problems occur with this arrangement, whichconsiderably hamper the function of the godet roll. First, the godetroll casing is only insufficiently heated in the area of the magneticbearings, such that the yarn or yarns can be guided only in the centerarea of the godet roll casing in order to receive a thermal treatment ofthe yarn or yarns.

A further problem is caused by the arrangement of the sensors of themagnetic bearings provided within the annular space for detecting theposition of the godet roll casing. With the godet rolls customarily usedconventionally, temperatures of approximately 230 degrees Celsiusprevail in the interior of the godet roll casing, which directly affectthe sensors. Since the magnetic seating requires a very exactdetermination of the seating of the godet roll casing, and thereforerequires very sensitive sensors which, however, can hardly toleratethese high temperatures, a dependable detection of the seating of thegodet roll casing, and therefore exact seating by means of the magneticbearings, is not assured.

SUMMARY OF THE INVENTION

It is therefore a basic object of the present invention to provide animproved godet roll of the type described above and, more particularly,to provide a godet roll wherein uniform heating of the godet roll casingis possible without a deleterious effect on the magnetic seating of thegodet roll casing. It is a further object of the present invention toenable the detection of the position of the godet roll casingessentially unaffected by the heating device.

In accordance with the present invention, these objects are addressed byproviding a godet roll wherein at least one of the heating pole windingsis arranged in a bearing plane between the bearing pole windings of thebearing plane and wherein a plurality of sensors are provided outsidethe annular chamber for determining the position of the godet rollcasing and are connected with a control device for controlling thebearing pole windings.

Such a godet roll of the present invention is particularly distinguishedin that the bearing areas of the godet roll casing can be directlyheated. At least one of the heating pole windings is arranged in one ofthe bearing planes between the bearing pole windings of the bearingplane for this purpose. A bearing plane is defined as that normal planeof the godet roll in which the bearing pole windings are arranged.Therefore, the godet roll casing is not only radially supported in thebearing plane, but is simultaneously heated by the current generated bythe heating pole winding. In such case, the air gap set between theheating pole windings and the godet roll casing is a function of thebearing gap controlled between the bearing pole windings and the godetroll casing. Therefore, the combination of the present invention allowsthe setting of the smallest air gaps, so that a loss-resistant heatingof the godet roll casing is possible. The heating pole windings, as wellas the bearing pole windings, can act in the same or in oppositedirections. When acting in the same direction, the air gap and thebearing gap are formed between the pole ends and the godet roll casing.When acting in the opposite direction, the air gap is formed between thegodet roll casing and the pole ends of the heating windings, and thebearing gap is formed between a hub or shaft and the pole ends of thebearing windings.

A further feature of the present invention is particularly advantageousfor obtaining a seating of the godet roll casing which is as rigid andvibration-free as possible, and therefore an air gap between the heatingpole windings and the godet roll casing extends uniformly over theentire length of the godet roll casing. According to this feature of theinvention, the bearing pole windings of the magnetic bearing aredistributed over at least three bearing planes, with at least some ofthe heating pole windings of the heating device being provided in thebearing planes between the bearing pole windings. A distribution of thebearing pole windings over several bearing planes has the advantage thata flat seating, and therefore a flat support of the godet roll casing,is achieved. Thus, the distribution of the bearing pole windings and theheating pole windings over the support provides for a uniformdistribution of the positions at which a force is introduced for theradial seating of the godet roll casing, as well as induced currents forheating the godet roll casing. Thus, the tendency of the godet roll tobecome deformed at high speeds, for example to bend in case ofsympathetic vibrations, is reduced by the flat seating of the godet rollcasing.

In accordance with another advantageous development of the invention,the heating pole bearings and/or the bearing pole windings can bedistributed over a support at offsets relative to each other from onebearing plane to another bearing plane. In case of such an angularoffset arrangement of two pole windings, the angular position of asecond pole winding in a second bearing plane is differentiated from afirst bearing winding in a first bearing plane. The angular position ofa pole winding is the position of the pole winding at the circumferenceof the support. If a position perpendicularly above the axis of rotationis selected as the reference position, the angular positionsperpendicularly below the axis of rotation are 180 degrees spacedtherefrom, and those of the lateral position on the level of the axis ofrotation are 90 degrees and 270 degrees spaced therefrom.

With an angularly offset arrangement of the bearing pole windings, thedirections from which a force is exerted on the godet roll casing vary.This arrangement makes possible a radial seating of the godet rollcasing with an arrangement of only one or two bearing pole windings inone bearing plane, so that a relative large installation space forreceiving the heating pole windings is available in the bearing plane.In the process, the bearing pole windings of different bearing planescooperate.

In accordance with another aspect of the present invention, aspirally-shaped arrangement of at least some heating pole windingsand/or bearing pole windings from one bearing plane to the next achievesfurther uniformity in the distribution of the bearing pole windings onthe support. In this connection, it is also possible to combine theheating pole windings of one bearing plane in a common heating zone. Insuch case, the godet roll casing would be divided in the axial directioninto a plurality of heating zones, such that each one of the heatingzones can be heated by at least one, or several, heating pole windings.

However, it is also possible to arrange the heating pole windings and/orthe bearing pole windings overlappingly in the circumferential directionof the support. In this manner, it is possible to achieve a uniform andlarge energy density, particularly for heating the godet roll casing.

The provision of the godet roll of the present invention with severalsensors arranged outside of the annular space for determining theposition of the godet roll casing, so that no thermal overload of thesensors can occur, represents a further attainment of the basic objectof the invention. The sensors are coupled with a control device whichcontrols the bearing pole windings. In such case, the sensors can bepositioned at locations at which the surroundings permit a sensitiveposition measurement in every operating range. It is presumed that thebearing gap changes occurring between the bearing pole windings and thegodet roll casing are propagated to each position connected with thegodet roll casing because of the rigidity of the godet roll casing.

According to a particularly preferred further development of theinvention, the sensors are arranged in the area of the bearing planes,wherein air gaps are formed between the godet roll casing and thesupport in the area of the bearing planes outside of the annular gap,with the bearing planes being essentially parallel in respect to abearing gap formed between the godet roll casing and the pole ends ofthe bearing pole windings. Here, the sensors for monitoring the air gapsare embodied as distance sensors. This arrangement allows a verysensitive and delicate position determination, which assures the exactcontrol of the magnetic bearings.

In such an embodiment, the air gaps can be formed, on the one hand, on afree end of the support inside the godet roll casing between a hubconnected with the godet roll casing or, on the other hand, on theclamped end of the support outside of the godet roll casing between thegodet roll casing and a collar connected with the support. In thismanner, the position of the godet roll casing can be determined at bothends, so that an alignment by means of the magnetic bearing is assured.

A particularly advantageous further development of the inventionprovides for a sensor to be assigned to each bearing pole winding, suchthat the bearing pole windings are each separately controllable by meansof the control device. This embodiment is particularly advantageous withan arrangement of individual bearing pole windings in individual bearingplanes for the possible arrangement of several heating pole windings inthe bearing planes.

However, it is also possible to control the bearing pole windings inpairs by means of the control device. In this case, a pair of bearingpole windings can be arranged in one or in two bearing planes.

In another embodiment, the godet roll casing is seated by means of anadditional axial bearing for absorbing the axial forces. The axialbearing is preferably designed as an axially acting magnetic bearing.However, it is also possible to constitute the axial bearing by means ofrolling bearings of an axial or radial design.

To assure the emergency running of the godet roll casing, at least onecatch bearing is provided, which can be embodied as a contactless radialbearing or a resiliently connected radial bearing.

Exemplary embodiments of the godet roll in accordance with the presentinvention will be described in greater detail in the followingdisclosure, with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are schematic cross-sectional views of a first exemplaryembodiment of a godet roll in accordance with the present invention, and

FIGS. 3 and 4 are schematic cross-sectional views of a further exemplaryembodiment of a godet roll in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A first exemplary embodiment of the godet roll in accordance with theinvention is represented in FIGS. 1 and 2. FIG. 1 shows the elements ofthe godet roll which are essential for the invention, depicted by meansof a cross-section taken parallel to and through the axis of rotation,and FIG. 2 schematically shows cross-sections taken perpendicularly tothe axis of rotation, a section through one of the bearing planes A—Abeing represented in FIG. 2.1, and a section taken along line B—Boutside of the bearing planes being represented in FIG. 2.2.

Therefore the following description applies to each of the drawings ofFIGS. 1, 2.1 and 2.2, whether or not an explicit reference is made toone of the drawing figures.

The exemplary embodiment of the godet roll in accordance with theinvention has a godet roll casing 1, which is fixedly connected via afront wall 2 and a hub 16 with a shaft 3 extending inside the godet rollcasing 1 against relative rotation therebetween. The opposite end of theshaft 3 is connected via a coupling 7 to a drive shaft 8 of a motor 9.The motor 9, preferably embodied as an electric motor, is shown in aplan view in FIG. 1.

The godet roll casing 1 is seated on a projecting support 4 by means oftwo radially acting magnetic bearings 13.1, 13.2, which are arrangedinside an annular chamber 17 formed between the godet roll casing 1 andthe projecting support 4. The magnetic bearings 13.1, 13.2 are attachedat a distance from each other on the support 4, with the magneticbearing 13.1 being located at a free end of the support 4, and themagnetic bearing 13.2 being located in the area of the fixedly clampedend of the support 4. The support 4 is embodied as a hollow cylinder andextends inside the godet roll casing 1 up to a short distance from thefront wall 2. In this embodiment, the support 4 is penetrated by the hub16 and the shaft 3. On the end opposite the front wall 2, the support 4is fastened on a frame 6 by means of a collar 5.

The magnetic bearings 13.1, 13.2 each have four bearing pole windings10.1 to 10.4, which are arranged at relative spacings on the support 4within respective bearing planes 14.1 and 14.2. Each one of the bearingpole windings 10 is comprised of an exciter winding 11 and a poleelement 12. The bearing pole windings 10.1 to 10.4 of each of themagnetic bearings 13.1 and 13.2 are arranged on the support 4 in eachrespective bearing plane 14.1 and 14.2 at angularly offset spacings fromone another. Here, the angular offset is 90 degrees. This arrangement isrepresented in FIG. 2.1, wherein FIG. 2.1 represents a cross-sectionthrough the magnetic bearing 13.1, as well as a cross-section throughthe magnetic bearing 13.2.

A heating device 29 for heating the godet roll casing 1 is arranged onthe circumference of the support 4. For this purpose, the heating device29 has a plurality of heating pole windings 30, which are arranged nextto each other and essentially uniformly distributed in the axialdirection of the support 4 as well as in the radial direction of thesupport 4. Some of the heating pole windings 30 are arranged on thesupport 4 in the bearing planes 14.1 and 14.2 between the bearing polewindings 10. Each one of the heating pole windings 30 is comprised of apole element 31 and an exciter winding 32. The exciter windings 32 ofthe heating pole windings 30 are connected together, or in groupsconstituting individual heating zones, with a heater control 34. Theheater control 34 is located on the power take-off side of the godetroll.

A cross section of one of the bearing planes 14.1 or 14.2 (FIG. 2.1), aswell as a cross section through the center area of the godet roll (FIG.2.2), are represented in FIG. 2. The support 4 is designed as a polygonfor receiving the heating pole windings 30 and the bearing pole windings10. In the illustrated embodiment, a total of eight outer faces isprovided on the support 4, to which the pole elements 12 of the bearingpole windings 10 and the pole elements 31 of the heating pole windings30 are fastened. In this embodiment, as represented in FIG. 2.1, thebearing pole windings 10.1 to 10.4 of the magnetic bearing 13.1 arerespectively arranged on four outer faces of the support 4 such that thebearing pole windings 10.1 to 10.4 are respectively offset from oneanother by 90 degrees. One heating pole winding 30 is located on each ofthe other outer faces of the support 4 formed between the bearing polewindings 10.1 to 10.4. An air gap 35 is formed between the pole ends ofthe heating pole windings 30 and the godet roll casing 1. A bearing gap15 is formed between the pole ends of the bearing pole windings 10 andthe godet roll casing 1. The gap widths of the bearing gap 15 and theair gap 35 can be of equal size or embodied to be different.

A cross section outside of the bearing planes 14.1 and 14.2 isrepresented in FIG. 2.2. Here, the respective pole elements 31 of theheating pole windings 30 are fastened on the eight outer faces of thesupport 4. Thus, a total of eight heating pole windings 30 are arrangedin an angularly offset manner on the support 4, the angular offset inthis case being 45 degrees. The air gap 35 is formed between the poleends of the heating pole windings 30 and the godet roll casing 1.

From the illustration in FIG. 1, it can be seen that the diameter of thecollar 5 of the support 4 at its end adjacent the frame 6 is greaterthan the two matching diameters of the front wall 2 and the godet rollcasing 1. The collar 5 of the support 4 has an annular flange 23extending toward the godet roll casing 1, which covers a shoulder 22formed on the end of the godet roll casing 1 at a spacing therefrom.Several sensors 19 facing toward the shoulder 22 of the godet rollcasing 1 are arranged on the radially inward surface of the flange 23. Atotal of four sensors 19.1 to 19.4 are provided, with only the sensors19.1 and 19.3 being visible in FIG. 1, the sensors 19.1 to 19.4 beingrespectively assigned to the bearing pole windings 10.1 to 10.4 of themagnetic bearing 13.2. The sensors 19.1 to 19.4 serve as distancesensors for detecting the position of the godet roll casing 1 and areconnected with a control device 20 via signal lines, not represented inthe drawings. The control device 20 is connected via control lines withthe exciter windings 11 of the bearing pole windings 10.1 to 10.4 of themagnetic bearing 13.2.

For monitoring the godet roll casing 1, the air gap formed between thesensors 19 and the shoulder 22 is monitored.

A recess 36 is formed on the support 4 at the free end of the support 4interiorly of the support in the area of the bearing plane 14.1. Severalsensors 19.1 to 19.4 are fastened on the support 4 in the notch 36 atangular offsets with respect to each other within a common plane. Inthis case, the sensors 19.1 to 19.4 are assigned to the bearing polewindings 10.1 to 10.4. Hereagain, the sensors 19.1 to 19.4 are coupledvia signal lines with the control device 20. The exciter windings 11 ofthe bearing pole windings 10 of the magnetic bearing 13.1 are controlledvia the control device 20. To detect the position of the godet rollcasing 1, an air gap formed between the sensors 19 and the hub 16 ismonitored.

In order to absorb axial forces of the godet roll casing 1, as well asfor the start-up and emergency seating, two radial bearings 24.1 and24.2 are provided. In this case, the ends of the support 4 have annulardepressions facing toward the hub 16 of the godet roll casing 1, each ofwhich receives one of the radial bearings 24.1 and 24.2 arranged on thesupport 4. Here, the radial bearings 24.1 and 24.2 are respectivelyarranged via a sleeve 33 between the support 4 and the hub 16. For thispurpose, the sleeve 33, for example, could be equipped with a metal ringat the radially inward side of the sleeve for receiving the radialbearing 24, and an elastomer ring at the radially outward side forengaging the support 4. With this arrangement, a dependable start-up, oremergency running of the godet roll casing independently of the magneticbearing, is assured. The radial bearings 24.1 and 24.2 are bracedagainst each other for absorbing the radial force, shown by way ofexample by means of several locking rings.

During operation, the actual position of the godet roll casing ismeasured by the sensors 19 in the area of the bearing planes 14.1 and14.2, and the measured values are forwarded to the control device 20.The position of the godet roll casing in the bearing planes 14.1 and14.2 is determined in the control device 20 from the measured values andthe individual exciter windings 11 of the bearing pole windings 10 ofthe magnetic bearings 13.1 and 13.2 are actuated in accordance with thedesired correction of the position. In this case, the bearing polewindings of one of the magnetic bearings 13.1 or 13.2 are actuatedeither individually or in pairs, so that the position of the godet rollcasing 1 takes up the desired position.

The godet roll casing 1 is simultaneously heated by means of thecurrents induced in the godet roll casing 1 by the heating pole windings30. One or several temperature sensors (not represented in the drawings)are provided for regulating the surface temperature of the godet rollcasing, which are connected via signal lines with the heater control 34and therefore make a set point adjustment of the surface temperaturespossible. The exciter windings 32 of the heating pole windings 30 arecontrolled in accordance with the signals by the heater control 34. Inan embodiment which establishes several heating zones, one temperaturesensor is assigned to each respective heating zone, which makes possiblethe actuation of the heating pole windings of each respective heatingzone via the heater control for reaching a preselected set pointtemperature. Essentially the entire casing area of the godet roll casing1 is heated by means of the arrangement of the heating pole windings 30in accordance with the invention. In this manner, the areas in thebearing planes can also be used for yam guidance and yarn treatment.

A further exemplary embodiment of the godet roll in accordance with thepresent invention is represented in FIGS. 3 and 4. Here, FIG. 3 shows aschematic longitudinal section through the elements of the godet rollessential for the invention, and FIGS. 4a) to 4 g) each show a crosssection through the bearing planes of the godet roll. Components withthe same functions are provided with identical reference numerals.

The following description applies to FIGS. 3 and 4, except in cases ofexplicit references made to one of the drawing figures. This exemplaryembodiment essentially corresponds to the exemplary embodiment of thegodet roll in accordance with the invention in FIG. 1, so that only thedifferences will be explained in the following description. In thisembodiment, the godet roll casing 1 is seated on the projecting support4 by means of only one magnetic bearing 13. For this purpose, themagnetic bearing 13 has a total of fourteen bearing pole windings 10.1to 10.14, which are arranged in pairs opposite each other, each in onebearing plane 14. Thus, the bearing pole windings 10.1 to 10.14 aredistributed within a total of seven bearing planes 14.1 to 14.7. Theangular positions of the two bearing pole windings 10.1 and 10.2 to10.12 and 10.14 in the bearing planes 14.1 to 14.7 are 0 degrees and 180degrees, 60 degrees and 240 degrees, 120 degrees and 30 degrees, 0degrees and 180 degrees, 60 degrees and 240 degrees, 120 degrees and 300degrees and 0 degrees and 180 degrees, i.e. the bearing pole windings10.1 to 10.14 are arranged at angular offsets from bearing plane tobearing plane. The bearing pole windings 10.1 to 10.14 thusly form twospirals around the axis of rotation 18, each with two revolutions ofconstant rise.

Each of the bearing pole windings 10.1 to 10.14 have cylindrical poleelements 12, around which exciter windings 11 are wound. The poleelements 12 of the bearing pole windings 10.1, 10.2 to 10.13, 10.14 arearranged in pairs in their respective bearing plane 14 on two oppositelylocated outer faces of the section 26 of the support 4, also embodied ina hexagonal cross-sectional configuration.

Several heating pole windings 30 of a heating device are arranged on thesupport 4 between the bearing pole windings 10.1 to 10.14, whichinductively heat the godet roll casing. For this purpose, the heatingpole windings 30 are arranged in each bearing plane on the remainingouter faces of the section 26 of the support 4 which are not occupied bythe bearing pole windings. Here, the heating pole windings 30 arecomprised of a pole element 31 and an exciter winding 32. The exciterwindings 32 are connected via control lines to a heater control 34. Theuniform distribution of the bearing pole windings 10.1 to 10.14 on thesupport 4 also makes possible a uniform distribution of the heating polewindings 30 on the support 4, and thus uniform heating of the godet rollcasing 1, besides the flat seating.

The sensors 19 have been omitted from FIGS. 3 and 4 for the sake ofclarity.

A magnetic axial bearing 23 is located on the shoulder 22 of the godetroll casing 1. The bearing pole elements with their exciter windings ofthe axial bearing 23 are arranged on a step 21 of the collar 5 of thesupport 4 and face in the direction toward the shoulder 22 of the godetroll casing 1.

Moreover, at least one mechanical contactless radial bearing 24 isprovided as a catch bearing. In the illustrated embodiments, the ends ofthe support 4 have annular recesses facing in the direction toward thehub 16 of the godet roll casing 1, each of which recesses receives oneof the radial bearings 24 arranged on the support 4.

During operation, the cooperation between the bearing pole windings 10.1to 10.14 takes place, for example, in case of defined faulty positionsof the godet roll casing, by actuating defined bearing pole windings10.1 to 10.14.

In this case, every one of the bearing pole windings 10.1 to 10.14 actsto attract the godet roll casing 1. For correcting the position of thegodet roll casing 1, the force of individual bearing pole windings isincreased by increasing the current applied to the corresponding exciterwindings 11. The current strength, and therefore the force on the godetroll casing, can remain constant.

It would alternatively be possible to keep the entire current strengthfor the bearing pole windings 10.1 to 10.14 constant and to only performa redistribution of the partial current strengths supplied to theindividual bearing pole windings 10.1 to 10.14 for correcting theposition of the godet roll casing 1.

The exemplary embodiments represented in FIGS. 1 to 4 of a godet roll inaccordance with the present invention are shown by way of example as totheir construction and their arrangement of the components. The presentinvention also extends to other exemplary embodiments not represented,wherein at least one heating pole winding is arranged in the bearingplanes between the bearing pole windings for heating the bearing area atthe godet roll casing. For example, the bearing area could extendbetween an interior shaft or hub and the bearing pole winding actingtoward the interior.

It will therefore be readily understood by those persons skilled in theart that the present invention is susceptible of broad utility andapplication. Many embodiments and adaptations of the present inventionother than those herein described, as well as many variations,modifications and equivalent arrangements, will be apparent from orreasonably suggested by the present invention and the foregoingdescription thereof, without departing from the substance or scope ofthe present invention. Accordingly, while the present invention has beendescribed herein in detail in relation to its preferred embodiment, itis to be understood that this disclosure is only illustrative andexemplary of the present invention and is made merely for purposes ofproviding a full and enabling disclosure of the invention. The foregoingdisclosure is not intended or to be construed to limit the presentinvention or otherwise to exclude any such other embodiments,adaptations, variations, modifications and equivalent arrangements, thepresent invention being limited only by the claims appended hereto andthe equivalents thereof.

What is claimed is:
 1. A godet roll for guiding, heating and conveyingyarn, the godet roll comprising a projecting support extending in alongitudinal direction, a drivable hollow-cylindrical godet roll casingforming a circumferential yarn guiding surface, at least one radiallyacting bearing rotatably seating the godet roll casing on the projectingsupport in at least one radially extending bearing plane, the radiallyacting bearing comprising a plurality of bearing pole windings in saidbearing plane, and a heating device, comprising a plurality of heatingpole winding, on the support, the bearing pole windings and the beatingpole windings being arranged within an annular chamber between thesupport and the godet roll casing, whereby at least one of the heatingpole windings is arranged in said radially extending bearing planebetween at least two bearing pole windings in the same radiallyextending bearing plane.
 2. The godet roll in accordance with claim 1,characterized in that the bearing pole windings of the magnetic bearingsare arranged in at least three radially extending bearing planes, and atleast some of the heating pole windings are arranged in the bearingplanes between the bearing pole windings.
 3. The godet roll inaccordance with claim 1, characterized in that one or both of theheating pole windings and the bearing pole windings are arranged on thesupport at angular offsets from bearing plane to bearing plane.
 4. Thegodet roll in accordance with claim 1, characterized in that one or bothof the beating pole windings and the bearing pole windings are arrangedin overlapping relation in the circumferential direction of the support.5. The godet roll in accordance with claim 1, characterized in that aplurality of sensors are provided outside the annular chamber fordetermining the position of the godet roll casing and are connected witha control device for controlling the bearing pole winding.
 6. A godetroll in accordance with claim 1 having a plurality of sensors providedoutside the annular chamber for determining the position of the godetroll casing, and a control device connected with the sensors forcontrolling the bearing pole winding.
 7. The godet roll in accordancewith claim 6, characterized in that the sensors are arranged in the areaof the bearing planes, air gaps are formed outside of the annularchamber in the area of the bearing planes between the godet roll casingand the support, the air gaps extending essentially parallel in relationto a bearing gap formed between the godet roll casing and pole ends ofthe bearing pole windings, and the sensors are designed as distancesensors for monitoring the air gaps.
 8. The godet roll in accordancewith claim 7, characterized in that one of the air gaps is formed at afree end of the support inside the godet roll casing between a hubconnected with the godet roll casing and the support.
 9. The godet rollin accordance with claim 7, characterized in that one of the air gaps isformed at a mounted end of the support outside of the godet roll casingbetween the godet roll casing and a collar connected with the support.10. The godet roll in accordance with claim 6, characterized in that oneof the sensors is assigned to each one of the bearing pole windings, andthe bearing pole windings are each individually controllable by means ofthe control device.
 11. The godet roll in accordance with claim 10,characterized in that the bearing pole windings are controllable inpairs by the control device.
 12. The godet roll in accordance with claim1, characterized in that the godet roll casing is seated by means of anadditional axial bearing, the axial bearing comprising an axially actingmagnetic bearing.
 13. The godet roll in accordance with claim 1,characterized in that at least one catch bearing is provided, the catchbearing comprising a contactless radial bearing or as a resilientlyclamped radial bearing.